Note: this summary has been translated by a fan, and is therefore unofficial.

As they're leaving to deactivate a tower on the Cortex, Aelita, Odd and Ulrich fall into a trap set by Ikonov. They find themselves trapped in a strange sphere that propels them several hours back in time in the middle of gym class. There, they frightfully realise that they are prisoners of a temporal loop. There's only one solution to get out of it: warn Jeremy. But how do they do that, when they're not in the same space-time?

Detailed summary

Odd, Aelita, Yumi and Ulrich are on an urgent mission in the Cortex, Odd at the wheel. Or at least, it seems like a mission. They race out of the Megapod and into the Dome, bounding from platform to platform until Aelita seemingly inserts a card into the interface, the others taking combat positions around her. Jeremy announces the result: 22 minutes and 12 seconds, a new record! Odd is the chosen driver in case they need to implant the virus in an emergency. Unless Ulrich can beat his record, of course. The Lyoko Warriors exit the Dome.

But as they approach the Megapod, it dematerialises right in front of their noses. It wasn't Jeremy who did it, and he can't seem to reprogram it. The mission is aborted, and the teens have to get back to the Skidbladnir on foot.

The next day, Jeremy hasn't managed to pinpoint the source of the bug. The Megapod can't be materialised anymore, and he has no idea why. He decides to skip gym class to work on the problem even more.

Outside gym class, Odd is nervously waiting for a phone call. But it's not a girl this time; he's waiting for tickets to the next Pumpkins Machine concert. While describing the supposed greatness of the upcoming concert, he bumps into Laura, causing her to drop her papers. Odd offers to help, but Laura notices a card among her belongings. The card Graven gave to her when she was still part of the group; “Quantum Research Center - Switzerland”. But she can't remember where she got it from.

Everything is calm in the Cortex. Suddenly, the Megapod materialises. Jeremy is elated: it was a simple conflict with a scanning program he had running. And speaking of which, this program activates, detecting an activated tower on the Cortex.

At the school, Odd is complaining about not winning the tickets to Aelita and Ulrich when Jeremy calls. The bespectacled boy doesn't know exactly what the attack is, but he knows that it needs to be deactivated. Yumi manages to get out of science class by acting sick, but William has to stay behind to finish their experiment.

The Lyoko Warriors arrive in the Arena, happy to find out that they don't need to go across the Cortex on foot because Jeremy had fixed the problem. There is still no telling what XANA's attack could be, so each of the teens are equally worried about what awaits them.

Laura contemplates the card she found that morning, taking out her phone and dialling the number. She explains who she is and how she got their number, and the voice on the other end organises a meeting later on via webcam.

The Megapod stops a few metres away from a tower with a violet halo. The four Lyoko Warriors are transferred outside the vehicle and observe the structure with wide eyes. Suddenly, Jeremy sees signals appearing on his screen around his friends. Five Ninjas suddenly appear, preparing to attack. That's when it clicks in Jeremy's mind: it wasn't XANA who activated the tower, it was Tyron! The attack was just bait to lure them to the Cortex, and into a trap!

In the middle of their fight with the Lyoko Warriors, the Ninjas suddenly stop, standing in a circle around their enemies. A glowing circle forms around the gang as an enormous sphere rises from the ground and begins to trap them inside! Yumi, just on the outside of the circle, has time to jump out before the sphere closes completely!

Odd, Ulrich and Aelita find themselves among the rest of their class in the gym! Jim begins a speech about not sleeping...the same speech he made earlier that day. Odd's phone rings and it is confiscated for the second time that day. The Lyoko Warriors have gone back to that morning's class!

Jim begins a speech about not sleeping...the same speech he made earlier that day...and just a few minutes ago. Odd's phone rings and it is confiscated for the third time that day. The Lyoko Warriors didn't just go back in time; they're stuck in a time loop.

Yumi bangs her fist against the sphere's opaque shell, begging her friends to answer. Jeremy can't see their signal; it's as if they've disappeared from the Cortex. William is sent in to help, setting off on the Overbike.

The scene in the gym repeats yet again. Jeremy is the only one that can help them out of their situation, but they have no way of contacting him, seeing as they're back in the past. But then Aelita realises that they don't have to call the Jeremy in the future, but the Jeremy of the present.

The scene starts again. Odd calls Jeremy on his phone, annoying Jim for the umpteenth time. However, Odd continues to talk, running away from the teacher. The Jeremy of their past can't believe Odd, thinking it's one of his jokes again. Jim then confiscates the phone. But before Odd can receive punishment, the scene starts again! The past Jeremy hangs up and continues his work.

Yumi's fans are deflected off the sphere. William arrives and inspects the sphere, deciding to try his zweihander, but even it doesn't work. On Jeremy's end, he can't get any data from the sphere. It's like it doesn't exist.

Up in her dorm room, Laura is waiting excitedly. The clock ticks over to 1PM...the tablet beeps. She clicks on it. Tyron's face appears on the screen, but the girl obviously doesn't recognise him. He asks her how she got the card, but she only knows that she found it by chance in her bag. Tyron begins to describe his establishment: a place for young, gifted students like Laura to work on their passions with the correct equipment...a supercomputer, for example. But Laura claims she has never worked with one, discouraging Tyron a little.

The scene in the gym restarts. Odd tries to call Jeremy immediately, and Jim chases after him again. Odd orders Jeremy not to hang up and shimmies up the rope used in Jim's class, but the teacher doesn't follow. Odd continues talking to Jeremy, but he still believes it to be one of Odd's jokes. Odd assures him that he knows the future, and describes the cause of the Megapod's bug just before Jim makes him drop his phone. The Jeremy of the past finally believes him, deciding to send his future self a message.

Yumi and William are still having no luck with the sphere. Not even the Megapod's cannon can pierce it. Jeremy feels defeated...but at that moment, an envelope icon appears on the screen. It's a message from himself. He opens it and reads that his friends are stuck in a temporal loop. The sphere is a time bubble! But what for? After some thinking, Jeremy figures out that while they're stuck in the bubble, Tyron can work on the same time sequence! He therefore has a repetitive signal coming from Kadic. He can localise the school.

Suddenly, the ground beneath Yumi and William's feet begins to move. They find themselves on a slope, falling and sliding down it, but luckily landing on a lower platform. The sphere also begins to roll towards the void, and towards them! While fleeing, Yumi notices that there is a hole in the sphere. And they absolutely cannot fall into it! William is absorbed inside.

Back in the gym, Odd begins to dial Jeremy's number when William appears out of nowhere beside him.

Jeremy figures out that Tyron only needs four more time loops to get a sufficient signal, but he still can't figure out what to do about it. Yumi remembers that altering time takes up a lot of energy - hence why they limit the returns to the past - so if they reroute Tyron's supercomputer's energy flow, they may be able to break the sphere. Jeremy sends her to the Dome to implement the plan.

The idea is to create a conflict between two programs; the same problem Jeremy had that morning. Yumi makes her way to the interface and Jeremy sends her a card, which she inserts. Three Ninjas appear. Only one more time loop is needed for Tyron to find them.

Yumi fares decently against the Ninjas, until suddenly the Dome's power goes out. The plan worked! On the outside, the sphere suddenly explodes, freeing the Lyoko Warriors! Yumi smiles at the Ninjas and leaps off the platform, disappearing into pixels.

Back in the lab, Jeremy and the others thank Yumi for her quick thinking. The sphere was destroyed before the final loop Tyron needed. However...

...Tyron expresses his displeasure at Laura's only theoretical knowledge of quantum physics. Before hanging up, he shows her holograms of the Lyoko Warriors' virtual avatars, asking if she recognises them. She does; they look like caricatures of Jeremy Belpois' friends...

Memo

- Attack: No XANA attack. Tyron activates a tower to lure the Lyoko Warriors to the Cortex and trap them in a temporal loop, which he uses to create a signal that he can track to find their location.
- Virtualisations: William
- Devirtualisations: Yumi (by Jeremy)
- Visited Sector: Sector Five; Digital Sea; the Cortex
- Enemies met: Ninjas (5); Ninjas (3)

- Source codes remaining: Not revealed
- XANA's power: Not revealed

Trivia

About errors

- Jeremy has a wrist brace on his arm for part of the episode. During some shots in this time (typically reused shots of him typing) he isn't wearing it.